// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/renderer/pepper/host_array_buffer_var.h"

#include <stdio.h>
#include <string.h>

#include <memory>

#include "base/logging.h"
#include "base/memory/shared_memory.h"
#include "base/process/process_handle.h"
#include "content/common/pepper_file_util.h"
#include "content/renderer/pepper/host_globals.h"
#include "content/renderer/pepper/plugin_module.h"
#include "content/renderer/pepper/renderer_ppapi_host_impl.h"
#include "content/renderer/render_thread_impl.h"
#include "ppapi/c/pp_instance.h"

using blink::WebArrayBuffer;
using ppapi::ArrayBufferVar;

namespace content {

HostArrayBufferVar::HostArrayBufferVar(uint32_t size_in_bytes)
    : buffer_(WebArrayBuffer::create(size_in_bytes, 1 /* element_size */))
    , valid_(true)
{
}

HostArrayBufferVar::HostArrayBufferVar(const WebArrayBuffer& buffer)
    : buffer_(buffer)
    , valid_(true)
{
}

HostArrayBufferVar::HostArrayBufferVar(uint32_t size_in_bytes,
    base::SharedMemoryHandle handle)
    : buffer_(WebArrayBuffer::create(size_in_bytes, 1 /* element_size */))
{
    base::SharedMemory s(handle, true);
    valid_ = s.Map(size_in_bytes);
    if (valid_) {
        memcpy(buffer_.data(), s.memory(), size_in_bytes);
        s.Unmap();
    }
}

HostArrayBufferVar::~HostArrayBufferVar() { }

void* HostArrayBufferVar::Map()
{
    if (!valid_)
        return NULL;
    return buffer_.data();
}

void HostArrayBufferVar::Unmap()
{
    // We do not used shared memory on the host side. Nothing to do.
}

uint32_t HostArrayBufferVar::ByteLength()
{
    return buffer_.byteLength();
}

bool HostArrayBufferVar::CopyToNewShmem(
    PP_Instance instance,
    int* host_shm_handle_id,
    base::SharedMemoryHandle* plugin_shm_handle)
{
    std::unique_ptr<base::SharedMemory> shm(
        RenderThread::Get()
            ->HostAllocateSharedMemoryBuffer(ByteLength())
            .release());
    if (!shm)
        return false;

    shm->Map(ByteLength());
    memcpy(shm->memory(), Map(), ByteLength());
    shm->Unmap();

    // Duplicate the handle here; the SharedMemory destructor closes
    // its handle on us.
    HostGlobals* hg = HostGlobals::Get();
    PluginModule* pm = hg->GetModule(hg->GetModuleForInstance(instance));

    *plugin_shm_handle = pm->renderer_ppapi_host()->ShareSharedMemoryHandleWithRemote(
        shm->handle());
    *host_shm_handle_id = -1;
    return true;
}

} // namespace content
